The track laying train is the means by which rails habitually reach the railway track laying area, with the rails needing to be unloaded subsequently from the track laying train.
There are basically two methods for unloading the rails. They are differentiated by the fact that in one of them the track laying train advances over the track already laid while the rail is secured at a fixed point at one of its ends and, in the other method, the track laying train remains stationary while the rail is extracted following the track alignment. If the former method is used, a previously laid track is required, i.e. an auxiliary track, which could be a track to be replaced subsequently.
With the latter method, the track laying train remains stationary on the track, which can be the new track previously placed, and the new rails are progressively extracted to be placed as a continuation to the previously laid track.